Added driver for OLED displays sh1106 and ssd1306

RPiGPIOmakertools/drivers/OLED_SH1106_SSD1306.py

@@ -0,0 +1,249 @@
+#!/usr/bin/env python3
+
+# The MIT License (MIT)
+#
+# Copyright (c) 2015 Richard Hull
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+# Example usage:
+#
+#   from oled.device import ssd1306, sh1106
+#   from oled.render import canvas
+#   from PIL import ImageFont, ImageDraw
+#
+#   font = ImageFont.load_default()
+#   device = sh1106(port=1, address=0x3C)
+#
+#   with canvas(device) as draw:
+#      draw.rectangle((0, 0, device.width, device.height), outline=0, fill=0)
+#      draw.text(30, 40, "Hello World", font=font, fill=255)
+#
+# As soon as the with-block scope level is complete, the graphics primitives
+# will be flushed to the device.
+#
+# Creating a new canvas is effectively 'carte blanche': If you want to retain
+# an existing canvas, then make a reference like:
+#
+#    c = canvas(device)
+#    for X in ...:
+#        with c as draw:
+#            draw.rectangle(...)
+#
+# As before, as soon as the with block completes, the canvas buffer is flushed
+# to the device
+
+import smbus2
+from PIL import Image, ImageDraw
+
+
+class device(object):
+    """
+    Base class for OLED driver classes
+    """
+
+    def __init__(self, port=1, address=0x3C, cmd_mode=0x00, data_mode=0x40):
+        self.cmd_mode = cmd_mode
+        self.data_mode = data_mode
+        self.bus = smbus.SMBus(port)
+        self.addr = address
+
+    def command(self, *cmd):
+        """
+        Sends a command or sequence of commands through to the
+        device - maximum allowed is 32 bytes in one go.
+        """
+        assert(len(cmd) <= 32)
+        self.bus.write_i2c_block_data(self.addr, self.cmd_mode, list(cmd))
+
+    def data(self, data):
+        """
+        Sends a data byte or sequence of data bytes through to the
+        device - maximum allowed in one transaction is 32 bytes, so if
+        data is larger than this it is sent in chunks.
+        """
+        for i in xrange(0, len(data), 32):
+            self.bus.write_i2c_block_data(self.addr,
+                                          self.data_mode,
+                                          list(data[i:i+32]))
+
+
+class sh1106(device):
+    """
+    A device encapsulates the I2C connection (address/port) to the SH1106
+    OLED display hardware. The init method pumps commands to the display
+    to properly initialize it. Further control commands can then be
+    called to affect the brightness. Direct use of the command() and
+    data() methods are discouraged.
+    """
+
+    def __init__(self, port=1, address=0x3C):
+        super(sh1106, self).__init__(port, address)
+        self.width = 128
+        self.height = 64
+        self.pages = self.height / 8
+
+        self.command(
+            const.DISPLAYOFF,
+            const.MEMORYMODE,
+            const.SETHIGHCOLUMN,      0xB0, 0xC8,
+            const.SETLOWCOLUMN,       0x10, 0x40,
+            const.SETCONTRAST,        0x7F,
+            const.SETSEGMENTREMAP,
+            const.NORMALDISPLAY,
+            const.SETMULTIPLEX,       0x3F,
+            const.DISPLAYALLON_RESUME,
+            const.SETDISPLAYOFFSET,   0x00,
+            const.SETDISPLAYCLOCKDIV, 0xF0,
+            const.SETPRECHARGE,       0x22,
+            const.SETCOMPINS,         0x12,
+            const.SETVCOMDETECT,      0x20,
+            const.CHARGEPUMP,         0x14,
+            const.DISPLAYON)
+
+    def display(self, image):
+        """
+        Takes a 1-bit image and dumps it to the SH1106 OLED display.
+        """
+        assert(image.mode == '1')
+        assert(image.size[0] == self.width)
+        assert(image.size[1] == self.height)
+
+        page = 0xB0
+        pix = list(image.getdata())
+        step = self.width * 8
+        for y in xrange(0, self.pages * step, step):
+
+            # move to given page, then reset the column address
+            self.command(page, 0x02, 0x10)
+            page += 1
+
+            buf = []
+            for x in xrange(self.width):
+                byte = 0
+                for n in xrange(0, step, self.width):
+                    byte |= (pix[x + y + n] & 0x01) << 8
+                    byte >>= 1
+
+                buf.append(byte)
+
+            self.data(buf)
+
+
+class ssd1306(device):
+    """
+    A device encapsulates the I2C connection (address/port) to the SSD1306
+    OLED display hardware. The init method pumps commands to the display
+    to properly initialize it. Further control commands can then be
+    called to affect the brightness. Direct use of the command() and
+    data() methods are discouraged.
+    """
+    def __init__(self, port=1, address=0x3C):
+        super(ssd1306, self).__init__(port, address)
+        self.width = 128
+        self.height = 64
+        self.pages = self.height / 8
+
+        self.command(
+            const.DISPLAYOFF,
+            const.SETDISPLAYCLOCKDIV, 0x80,
+            const.SETMULTIPLEX,       0x3F,
+            const.SETDISPLAYOFFSET,   0x00,
+            const.SETSTARTLINE,
+            const.CHARGEPUMP,         0x14,
+            const.MEMORYMODE,         0x00,
+            const.SEGREMAP,
+            const.COMSCANDEC,
+            const.SETCOMPINS,         0x12,
+            const.SETCONTRAST,        0xCF,
+            const.SETPRECHARGE,       0xF1,
+            const.SETVCOMDETECT,      0x40,
+            const.DISPLAYALLON_RESUME,
+            const.NORMALDISPLAY,
+            const.DISPLAYON)
+
+    def display(self, image):
+        """
+        Takes a 1-bit image and dumps it to the SSD1306 OLED display.
+        """
+        assert(image.mode == '1')
+        assert(image.size[0] == self.width)
+        assert(image.size[1] == self.height)
+
+        self.command(
+            const.COLUMNADDR, 0x00, self.width-1,  # Column start/end address
+            const.PAGEADDR,   0x00, self.pages-1)  # Page start/end address
+
+        pix = list(image.getdata())
+        step = self.width * 8
+        buf = []
+        for y in xrange(0, self.pages * step, step):
+            i = y + self.width-1
+            while i >= y:
+                byte = 0
+                for n in xrange(0, step, self.width):
+                    byte |= (pix[i + n] & 0x01) << 8
+                    byte >>= 1
+
+                buf.append(byte)
+                i -= 1
+
+        self.data(buf)
+
+
+class canvas(object):
+    """
+    A canvas returns a properly-sized `ImageDraw` object onto which the caller
+    can draw upon. As soon as the with-block completes, the resultant image is
+    flushed onto the device.
+    """
+    def __init__(self, device):
+        self.image = Image.new('1', (device.width, device.height))
+        self.device = device
+        self.draw = ImageDraw.Draw(self.image)
+
+
+class const:
+    CHARGEPUMP = 0x8D
+    COLUMNADDR = 0x21
+    COMSCANDEC = 0xC8
+    COMSCANINC = 0xC0
+    DISPLAYALLON = 0xA5
+    DISPLAYALLON_RESUME = 0xA4
+    DISPLAYOFF = 0xAE
+    DISPLAYON = 0xAF
+    EXTERNALVCC = 0x1
+    INVERTDISPLAY = 0xA7
+    MEMORYMODE = 0x20
+    NORMALDISPLAY = 0xA6
+    PAGEADDR = 0x22
+    SEGREMAP = 0xA0
+    SETCOMPINS = 0xDA
+    SETCONTRAST = 0x81
+    SETDISPLAYCLOCKDIV = 0xD5
+    SETDISPLAYOFFSET = 0xD3
+    SETHIGHCOLUMN = 0x10
+    SETLOWCOLUMN = 0x00
+    SETMULTIPLEX = 0xA8
+    SETPRECHARGE = 0xD9
+    SETSEGMENTREMAP = 0xA1
+    SETSTARTLINE = 0x40
+    SETVCOMDETECT = 0xDB
+    SWITCHCAPVCC = 0x2